1990 renix hard starting

1990 renix engine over heated, now its hard to start. could a bad battery cause this?

Could make it hard to start. Could not make it overheat.

Cranks good or won't crank?

Needs to crank a lot to start or won't start?

Need more details!

Also depends how bad it overheated. If the engine really got cooked, the head could be really warped and the valves won't also seat very well or the head gasket could be blown. I've seen on it a friend's jeep and he could not get his to start. You can check the compression to see if there are any low cylinders.

it runs ok wants you get it started, it seems like a fuel air mixture problem

Good battery and good grounds are absolutely essential to have your Renix start and run well.

cruiser54 said:

Good battery and good grounds are absolutely essential to have your Renix start and run well.

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Exactly!

Renix 101: why does a Renix 4.0 have to crank so much to start? The engine has to spin up to 300 RPM or faster before the Renix crank sensor will generate a strong enough signal to the ECU to fire the ICM/coil. Another problem with long cranking times is the fuel system is draining when shut off. This can be mitigated by turning the key to ON, wait 3-seconds, turn the key to OFF, repeat two more times, then try and start it. As Cruiser54 posted, without good grounds in a Renix you are going to have lots of ignition/electrical issues. The one and only unibody ground is the braided strap at the rear of the head that goes to the firewall. Chuck the strap and replace with a 2 ga. cable, make sure that you clean the surfaces down to bare metal, treat with an anti-corrosion material (any paint/hardware store), and make the connections TIGHT. Also, the ICM, ECU, o2 sensor, and other CRITICAL items ground to the dipstick tube--down to bare metal, anti-corrosion, and TIGHT. Adding a second unibody ground from the negative battery terminal to the fenderwell is an excellent idea.

joe_peters said:

Exactly!

Renix 101: why does a Renix 4.0 have to crank so much to start? The engine has to spin up to 300 RPM or faster before the Renix crank sensor will generate a strong enough signal to the ECU to fire the ICM/coil. Another problem with long cranking times is the fuel system is draining when shut off. This can be mitigated by turning the key to ON, wait 3-seconds, turn the key to OFF, repeat two more times, then try and start it. As Cruiser54 posted, without good grounds in a Renix you are going to have lots of ignition/electrical issues. The one and only unibody ground is the braided strap at the rear of the head that goes to the firewall. Chuck the strap and replace with a 2 ga. cable, make sure that you clean the surfaces down to bare metal, treat with an anti-corrosion material (any paint/hardware store), and make the connections TIGHT. Also, the ICM, ECU, o2 sensor, and other CRITICAL items ground to the dipstick tube--down to bare metal, anti-corrosion, and TIGHT. Adding a second unibody ground from the negative battery terminal to the fenderwell is an excellent idea.

Click to expand...

Couldn't have summed it up better myself. Start where Joe tells ya to.